A ‘quantum leap’ at room temperature

Now, a study led by Tobias J. Kippenberg and Nils Johan Engelsen at EPFL redefines the limits of what is possible. Early work combines quantum physics and mechanical engineering to control quantum phenomena at room temperature.

“Achieving room-temperature quantum opto-mechanics systems has been an open challenge for decades,” says Kupenberg. “Our work effectively makes sense of the Heisenberg microscope — long considered only a theoretical toy model.”

In their experimental setup, I published The naturethe researchers created an ultra-low-noise optomechanical system—a setup where light and mechanical motion are coupled, allowing them to study and manipulate how light affects moving objects with high precision. Affects with.

The main problem with room temperature is thermal noise, which disturbs the delicate quantum dynamics. To minimize this, scientists used cavity mirrors, which are special mirrors that bounce light back and forth within a confined space (cavity), effectively “trapping” it and the system. I increase its interaction with mechanical elements. To reduce thermal noise, glasses are patterned with crystal-like periodic (“phononic crystal”) structures.

Another key component was a 4mm drum-like device called a mechanical oscillator, which interacted with light inside the cavity. Its relatively large size and design are key to isolating it from environmental noise, making it possible to detect subtle quantum phenomena at room temperature. “The drum we use in this experiment is the result of many years of effort to create mechanical oscillators that are well isolated from the environment,” Engelson says.

“The techniques we used to deal with notorious and complex noise sources are of high relevance and impact to the broader precision sensing and measurement community,” says Guan Hao Huang, who led the project. One of two PhD students.

This setup allowed the researchers to capture “optical entanglement,” a quantum phenomenon where certain properties of light, such as its intensity or phase, cause fluctuations in one variable to decrease while increasing fluctuations in another. is added to the value, as per Heisenberg’s order. Principles

By demonstrating room-temperature optical squeezing in their system, the researchers showed that they can effectively control and observe quantum phenomena in macroscopic systems without the need for ultra-low temperatures. Top of the form

The team believes that the ability to operate the system at room temperature will expand access to quantum optomechanical systems, which have established testbeds for quantum measurements and quantum mechanics at the macroscopic scale.

“The system we developed could facilitate new hybrid quantum systems where the mechanical drum interacts strongly with different objects, such as entangled clouds of atoms,” said another Ph.D., who led the study. Student Alberto Beccari says. “These systems are useful for quantum information, and help us understand how to create large, complex quantum states.”